Fixated on Fixture Offsets

[Chris Rizzo]

Why are fixture offsets numbered 1,2,3,4,5,etc...in Mcam, and then converted by the post to g54,g55,g56,g57,g58,etc. for the machine?

 

I'm sure that there probably is a reason for this. Maybe if the programmer doesn't know the fixture offset order of a particular machine, he/she can just type 1,2,3,4,5 etc...without knowing the range of offsets are g54-g59, and then g110-g129. Maybe?

 

However in my small shop I know the control, and I'd prefer to just call them by the actual number in Mcam, instead of 1,2,3,etc. I've monkeyed around with the post a bit, but havn't figured it out yet. Before I call my dealer and inquire about him tweaking my post, I thought I'd get more ideas regarding this issue.

Thx y'all.

[Andy]

Hi,

I use a Fadal and we can use e1......e99 or g54....

I prefer e1, e2 etc. So for me it is an advantage to have FO #1, 2, etc

Andy

[Rick Damiani]

cmr:

 

The 'conversion' is done in the post. In MPFAN.PST, the postbloc responsible is pwcs, which looks like this:

 

code:

---

pwcs            #G54+ coordinate setting at toolchange

if mi1 > one,

[

sav_frc_wcs = force_wcs

if sub_level, force_wcs = zero

if workofs <> prv_workofs | (force_wcs & toolchng),

[

if workofs < 6,

[

g_wcs = workofs + 54

*g_wcs

]

else,

[

p_wcs = workofs - five

"G54.1", *p_wcs

]

]

force_wcs = sav_frc_wcs

!workofs

]

---

If you change it to something like this:

 

code:

---

pwcs            #G54+ coordinate setting at toolchange

if mi1 > one,

[

sav_frc_wcs = force_wcs

if sub_level, force_wcs = zero

if workofs <> prv_workofs | (force_wcs & toolchng),

[

g_wcs = workofs

]

force_wcs = sav_frc_wcs

!workofs

]

---

You should get what you are looking for. Just be careful about any automaticly assigned work offsets, such as those generated by transform tool paths and by the View Manager, as I am not sure that they will post correctly.

[Chris Rizzo]

Thanks Rick,

 

That's exactly what I'm looking for...However I plunked it into my MPHAAS post and now it's not outputting any fixture offsets. I'm going to try it in a MPFAN post and see if it works there..

[Chris Rizzo]

After a bit more screwing around, I figured out what I needed. Rick, you were real close, just missing one line... *g_wcs Thanks for the help!

 

code:

---

pwcs            #G54+ coordinate setting at toolchange

if mi1 > one,

[

sav_frc_wcs = force_wcs

if sub_level, force_wcs = zero

if workofs <> prv_workofs | (force_wcs & toolchng),

[

g_wcs = workofs

*g_wcs

---

Havn't tried it with transformations or parts with multiple faces and offsets yet...

[Jim Evans from CNC Software]

CMR,

 

We run the offests zero based to allow us to support multiple machines from the same MC9 file without having to change the offsets. For example, you program a part using 54, 55, 56 for your offset numbers and plan to use you Haas machining center. Well the hass is tied up but the fadal is open. If you are using the E1, E2,E3 on the fadal, you now have to change your MC9 file. Leaving it zero based requires no change in the MC9 file, just load the fadal post and post.

 

By keeping the offsets zero based and having the post calulate the correct offset, you can just post to any machine with out editing your MC9 file.

 

I hope this sheds some light on why we do it this way.

[Reece L Gibson]

I belive that's the way alot of things are set-up in the post. Thats what Jim has taught me.

Works pretty good too.

[Rick Damiani]

quote:

---

After a bit more screwing around, I figured out what I needed. Rick, you were real close, just missing one line... *g_wcs Thanks for the help!

---

Ooops. That's what I get for not testing it before I post it.

 

Glad you figured it out, though.

 

The modified block, for those paying along at home, should look like this:

 

code:

---

pwcs            #G54+ coordinate setting at toolchange

if mi1 > one,

[

sav_frc_wcs = force_wcs

if sub_level, force_wcs = zero

if workofs <> prv_workofs | (force_wcs & toolchng),

[

g_wcs = workofs

*g_wcs

]

force_wcs = sav_frc_wcs

!workofs

]

---

 

[ 05-22-2003, 03:38 AM: Message edited by: Rick Damiani ]

[Rick Damiani]

quote:

---

I hope this sheds some light on why we do it this way.

---

That is essentially the same thing I tell my students when they ask 'why is 0 equal to G54?'

 

I got nuthin' but HAAS at my school, but I leave that part of my post alone. Well, *mostly* alone....